Blood analysis is determination of the appearance, size and other characteristics of cells on the peripheral blood smear. These analyses can be followed by the examination of the bone marrow (puncture and biopsy), lymph nodes (puncture and biopsy), and spleen (puncture). Blood smears or punctates are stained with May-Grünwald-Giemsa solution (Pappenheim’s method).
General data about the size and appearance of the cell and their percentage are obtained from the smear.
The real size of the cell in the smear is changed because the cell widens and flattens. For example, the diameter of a live granulocyte is smaller in the blood than in the smear.
To adequately describe a cell it is necessary to calculate the nucleocytoplasmatic ratio (the ratio of the size of the nucleus and cytoplasm) that is equivalent to the nucleo-cellular ratio (the ratio of the size of the nucleus and the complete cell).
In less mature cells the nucleocytoplasmatic ratio is high and it decreases with the cell maturation.
Constituent parts of the cell that bind acid dye eosin are called eosinophilic or acidophilic. They are orange-red. The parts of the cells that bind methylblue are called basophilic. They are blue in color. Some parts of the cell may stain with both colors, and are called polychromatophilic. Some granules in the cytoplasm of blood cells can transform azure blue color into a red-bluish color – this is called metachromasia, whereas some other granules stain red with eosin-azure dye. These granules are called azurophilic granules.
When describing the nucleus of the cell we have to take into account its shape, location in the cell (centrally or eccentrically laid), color, general appearance of the nucleus, structure of its chromatin, and whether it contains nucleoli or not.
We also have to observe the intensity of the coloration of the cytoplasm, if it is stained evenly or not (the presence of unstained and brighter zones), and the type of granules, their number, color, size, and arrangement.
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